JPS62298736A - Rubber plate for measuring pressure distribution - Google Patents

Abstract

PURPOSE:To form an inexpensive and accurate pressure distribution measuring apparatus, by providing a plurality of grooves on both or one of the front and back surfaces of a rubber plate for measuring a pressure distribution to make independent pressure measuring sections divided into individual pressure receiving areas. CONSTITUTION:Grooves 2a and 2b perpendicular to each other are cut in both or one of sides of a rubber plate 1 for measuring a pressure distribution to form rectangular or square pressure sensing sections 3. The pressure sensor sections 3 are surrounded by the grooves to form independent pressure sensing sections. The rubber plate 1 employs natural rubber or silicone rubber with limited hysteresis loss to improve the reproducibility of measurement, linearity and response rate. Thus, a pressure distribution can be determined accurately with an inexpensive apparatus.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a pressure distribution measuring rubber plate used in a measuring device that quantitatively measures the distribution state of blood pressure. .

[Conventional technology]

Conventionally, methods for measuring the distribution of surface pressure include a method of distributing a large number of load detectors on a bar surface and a method of measuring the electrical conductivity of a pressure-sensitive rubber. The improvement method () is to use a capacitance method to measure blood pressure distribution, which can reduce the variation in characteristics depending on the measurement location, has good reproducibility of measurement, and has a straight line ↑ No. 1. It is valued for its good performance, low hysteresis, and low cost.

The outline of this capacitance method for measuring pressure is as follows: Spring materials (cushion, sponge, Amat, etc.) made of appropriately selected insulating materials, polymer phase, paper, LLI cloth, glass, etc. ) is sandwiched between two shielded electrode plates on both sides.A high-frequency signal is applied to one of the electrode plates, and a spring material is sandwiched between them. The high frequency signal that passes through and is transmitted to the other electrode plate is heterodyned (h
eterodyne) is received by a wave detector.

The basic structure of this sensor section consists of a shield layer from the outside,
It has a structure in which a spring material (insulator) is sandwiched from both sides by layers consisting of an insulating layer, an electrode layer, and a polyester film, and when a load W is applied perpendicularly to this layer, the thickness of the spring sheath t ta The magnitude of the load The output of the heterodyne detector is obtained as a function of the load W. Conventionally, pressurized conductive rubber or a rubber plate with good elasticity has been used for this spring material, and both have adopted a simple flat plate shape. Furthermore, for pressure distribution measurement using pressure-sensitive paper, a rubber plate having conical or chevron-shaped protrusions has been used.

[Problem that the invention seeks to solve]

None of the conventionally used rubber plate shapes described above allow accurate measurement of surface juice. This is because the amount of deformation due to pressure on a pressure-sensitive part changes depending on the shape factor of that part, so even if the same force per unit area is applied when the pressurized area is wide or narrow, the rubber deforms. The quantities will be different and the measured value will show an inaccurate value.

The goal is to solve the problem of the shape of the rubber plate so that the pressure per unit area and the amount of rubber deformation can always be determined correctly, and to greatly improve the accuracy of measurements. Note that the shape factor is the pressure-receiving area divided by the free area, and is one of the indicators of the ease with which the rubber plate deforms. For example, in a square prism, if one side of the square is a, the pressure receiving area is a2, and if the height of the square prism is b, the free area is 4ab.
It is displayed as a. Therefore, the shape factor is -Issho Hyakkoku -4b.

As mentioned above, the shape of the rubber plate of the pressure sensitive part, the required shape factor formed by a certain pressure receiving area and a certain free area are the primary matters for solving the problem. The objective is to use materials with low hysteresis loss, low aging resistance, and low fatigue resistance.

[Means for solving problems]

The present invention, which eliminates the above-mentioned drawbacks of the conventional technology, uses a rubber with a small hysteresis loss, for example, a rubber with an inorganic filler content of 10%.
By using peroxide-cured natural rubber or silicone rubber with a ratio of 50 parts or less of rubber to 0 parts, it improves measurement reproducibility, linearity by 1 point, and response speed by 1 point, while improving sensitivity. By making each pressure part independently separated at least in part by surrounding grooves, the relationship between pressure and strain on each pressure sensitive part can be adjusted to the distribution of surrounding pressure. In other words, the groove 61 rubber plate forms the required shape factor in which the pressure sensitive part is recessed by 1 in the surrounding groove. In this method, a pressure sensitive part formed independently on the inner side of the rubber plate by a peripheral groove is used as a pressure measuring part.

Note that details will be specifically explained based on exemplary drawings in the section of Examples.

[Effect]

Regarding the operation of this invention, the relationship between pressure and strain showing cross-sectional states under load is shown in Figure 6-(A>, (B)) and Figure 7-(A), (B), which are illustrated as basic explanatory diagrams. This will be explained in detail using a relationship diagram.

Figure 6 - (Δ), (8) is an explanatory diagram of the relationship between pressure and strain in the case of a conventional simple plate shape, where W is the load and R3P
is a flat rubber plate, and FIGS. 7-(a) and (b) are explanatory diagrams of the relationship between pressure and strain of the invention of this application, where W is the load;
GRP is a grooved rubber plate. The conventional example is shown in Fig. 6-(A>
, 03), a flat rubber plate R8P with a thickness h
Even if the same pressure load is applied per unit area of one side of the receiver, the amount of strain d1 and d2 will be as shown in Figure B>Figure A, and changes in pressurized conductivity and capacitance should originally show the same measured values. However, Figure A and Figure B will show different values.

That is, as shown in the relationship curve between strain amount and pressure per unit area in Figure 8, as shown by both curve A in Figure 6-(A>) and curve B in Figure 6-(B), The curve No.8 shows a larger amount of strain than the curve No.8.

Therefore, the invention of this application solves this drawback by one step, by adopting a grooved rubber plate as shown in the cross-sectional state under load in Fig. 7-(a) and (b). By isolating at least a portion of the pressure sensitive part with a surrounding groove,
The relationship between the pressure and strain of each pressure-sensitive part becomes constant, and the 8th
It has been found that no error occurs between the curve 8 and the curve shown in the figure. This is because, in Figure 7-1), even if the pressure-receiving area and free area of each pressure-sensitive part (in the figure, the lateral area of the pressure-sensitive part) are constant, the relationship between pressure and strain is always constant, Figure 7-(a) and Figure 7-(
The strain suspension d3 in b) is the same value, and the correct measured value is 1.
be qed.

〔Example〕

Example 1 In this example, a pressure sensitive section is formed by overlapping unit plates each having grooves formed on both sides.

1 is a partial perspective view of a grooved rubber plate of a unit plate of a rubber plate for measuring force distribution showing an example of the present invention; FIG. 2 is a partial sectional view taken along the line TI-II in FIG. 1; FIG. 3 shows that the LJI plates of FIG. 1 are superimposed at right angles, and the pressure receiving areas of the multiple pressure sensing parts of the square prisms are measured by the grooves around them, each as an independent pressure measuring part. This is a partially enlarged perspective view of only one pressure-sensitive part showing that a square prism-shaped pressure-sensitive part (dotted chain line) is formed, but the illustration is omitted. This is shown in the figure (groove portion not shown). In the figure, ] indicates a groove A 4 rubber plate, the surrounding groove consists of a horizontal groove 2a and a vertical groove 2b, and 3 is a pressure sensitive part, which is independently formed to a certain shape factor by the surrounding groove. It is something. In addition, the relationship between the height of the pressure sensitive part, the pressure receiving area, and the groove width should be selected appropriately by considering the ratio of the pressure receiving area to the height and the relationship between the size of the measured pressure so that the pressure sensitive part does not have a tendency to buckle. will be carried out.

Example 2 FIG. 4 of this example is a partial perspective view of a rubber plate for pressure distribution measurement of the present invention having grooves formed on one side.

In the figure, 1 is a grooved rubber plate with multiple horizontal grooves 2a,
One vertical groove 2b is provided on both sides of the rubber plate, and a pressure sensitive part 3 is set by forming a groove around the periphery.

Example 3 FIG. 5 of this example shows a rubber plate for measuring pressure distribution according to the present invention, in which a large number of horizontal grooves 2a and vertical grooves 2b are formed on one side of the rubber plate, and a pressure sensitive part 3 is formed by the peripheral grooves. FIG.

As shown in each of the above embodiments, the rubber plate for pressure distribution measurement of the present invention has a groove formed around the periphery so that the pressure receiving area of the pressure sensing portion is independent of the pressure measurement portion. Similarly to the other embodiments described above, the pressure receiving area and free area of each pressure sensitive part are formed to have a certain required shape factor.

Note that the shape of the pressure sensitive part is not limited to a square column, but may be a cylinder, a square column (square,
In addition to rectangular shapes, truncated cones, etc., they can be appropriately selected depending on the purpose, stress direction, relationship with the electrodes, etc. Furthermore, interference between the pressure sensitive parts can be reduced by providing a conductive material in the groove part.

〔Effect of the invention〕

In this invention, the rubber plate used as the conductive rubber sandwiched between the electrodes is made into a grooved rubber plate in which the pressure-sensitive parts are divided into individual parts, instead of the conventional flat plate shape, and the relationship between pressure and strain is determined. By setting -9= to be constant, a very accurate pressure distribution value can be obtained. In addition, in the configuration as in Example 1, electrode settings are much easier, and an advantage is obtained that an inexpensive pressure distribution measuring device can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a unit plate of a rubber plate for pressure distribution measurement according to an example of the present invention, FIG. 2 is a partial cross-sectional view taken along line ll-H in FIG. 1, and FIG.
FIG. 4 is a partially enlarged perspective view showing a part of the pressure sensitive part of the square prism of the present invention obtained by inserting the middle plate of the grooved rubber plate of FIG. 1; FIG. 4 is another embodiment of the present invention. Fig. 5 is a partial perspective view of a rubber plate for pressure distribution measurement showing another embodiment of the present invention; Fig. 6 - (A), (B) is an explanatory diagram of the relationship between pressure and strain of a conventional plain flat rubber plate, Figure 7-(a),
(B) is an explanatory diagram of the relationship between the pressure and strain of the grooved rubber plate. Figure 8 is a curve diagram showing the pressure and strain per unit area in Figure 6 - (A>, (13)). , the vertical axis is the amount of strain, and the horizontal axis is the pressure per medium area.

Claims (2)

[Claims] (1) When a rubber plate used in a device that measures pressure distribution is a combination of grooved rubber plates with grooves formed on both the front and back surfaces, or a grooved rubber plate with grooves formed on one side, the peripheral grooves allow pressure-sensitive parts to be A rubber plate for pressure distribution measurement, which is a grooved rubber plate structure in which each pressure receiving area forms an independent pressure measurement part. (2) Each pressure sensitive part of the pressure measuring part of the grooved rubber plate is a pressure sensitive part having a predetermined shape factor formed by a certain pressure receiving area and a certain free area by surrounding grooves. A rubber plate for pressure distribution measurement according to scope 1.